Correct Type annotation for __init__

问题

What is the correct type annotation for a __init__ function in python?

class MyClass:
    ...

Which of the following would make more sense?

def __init__(self):
    # type: (None) -> None

def __init__(self):
    # type: (MyClass) -> MyClass

def __init__(self):
    # type: (None) -> MyClass

Since we would normally instantiate as myclass = MyClass(), but the __init__ function itself has no return value.

回答1:

self should be omitted from the annotation when it is given as a comment, and __init__() should be marked as -> None. This is all specified explicitly in PEP-0484.

来源：https://stackoverflow.com/questions/46779046/correct-type-annotation-for-init